The cationic quaternary type of fatty derivation based on coconut, soybean or tallow fats has been the basis for the development of textile softening agents and/or cosmetic ingredients and other industrial uses. A typical tallow derived softening agent is the distearyl dimethyl quaternary ammonium chloride structure as indicated: EQU [(CH.sub.3).sub.2 --N--(C.sub.18 H.sub.37).sub.2 ].sup.+ Cl.sup.-
This is usually offered as a paste form at 75% solids in isopropanol or in lower dilutions in a mixture of isopropanol and water. This product has a very limited degree of water solubility, and exhibits irritation properties. Alternate methods employ an amide route including ethoxylation to develop other tallow based derivatives of higher polarity for improved water solubility, see U.S. Pat. No. 2,459,088. This is illustrated for another stearyl type quaternary: ##STR1## Compounds of this type have improved water solubility and softening properties. However, they are also fairly irritating. One recent development is the utilization of Lanolin fatty acids as a route for improving the irritation properties but this occurs at the expense of water solubility. A typical quaternary of this technology is illustrated: ##STR2## where Lan is defined as the mixed higher molecular weight fatty acids derived from Lanolin or wool fat.
In contrast to the prior art, the instant invention is directed to quaternized castor fatty acid based amido-amines prepared by (1) condensing a castor fatty acid with the amido protons of a diamine containing a tertiary amino group at one end to form a fatty amido-amine intermediate and then (2) quaternizing this intermediate with a quaternizing agent, and to these compounds used as softeners and fixatives. This invention takes advantage of the unique emollient and lubricating properties of the castor fatty acids which contain hydroxy groups capable of imparting extra softening, e.g. in textiles, and fixative properties so that the compounds do not easily wash out. Additionally the compounds have a high degree of water solubility and are not irritating. These properties are particularly useful in textile and cosmetic formulations such as fabric softeners, hair shampoos, etc. Unique cosmetic properties are also associated with compounds based upon castor based fatty acids which do not contain the hydroxy group and these compounds are included in this disclosure.
The castor based fatty acids preferably employed in the instant invention are ricinoleic acid, 12-hydroxystearic acid, and ethoxylated or propoxylated derivatives of ricinoleic acid or 12-hydroxystearic acid.
The general formula for the amido-amine intermediate condensation product derived from the fatty acid is illustrated by the following typical reaction: ##STR3## In general, amines having the formula: ##STR4## where
n=1 to 10;
R.sub.1 =H, saturated alkyl groups of CH.sub.3 through C.sub.10 H.sub.21, or alkenyl groups of C.sub.2 H.sub.4 through C.sub.10 H.sub.20 ; and, R.sub.2 and R.sub.3 can be the same as R.sub.1. R.sub.1, R.sub.2 and R.sub.3 do not have to be the same but are independently selected. Substituted aminopropylamines where n is three, particularly alkyl substituted, e.g. dialkyl substituted aminopropylamines are a preferred class of amines. N,N-dimethylaminopropylamine having the formula: ##STR5## is typical.
The quaternizing agents which can be used in this invention include benzyl chloride or alkyl chlorides, bromides, phosphates and sulfates, such as dimethyl sulfate, dimethyl bromide and diethylsulfate.
The quarternary compounds of this invention can be represented by the formula: ##STR6## where: n, R.sub.1, R.sub.2 and R.sub.3 have the meanings described above; R.sub.4 =12-hydroxystearyl, ricinoleyl, 12-(2-hydroxyproploxy) stearyl, 12-(2-hydroxyethyloxy) stearyl, or 12-(2-hydroxyethyloxy)oleyl 12-(2-hydroxypropyloxy) oleyl; R.sub.5 =benzyl or alkyl of 1 to 3 carbon atoms; and M=chloride, bromide, phosphate or sulfate. The 12-hydroxystearic acid and ricinoleyl acid derivatives are used to produce preferred water-soluble quarternary compounds in accordance with this invention.
It is preferred to carry out the reaction in the presence of a solvent such as, for example, propylene glycol or isopropanol. Although various amounts of solvent can be employed, it has been found that about 70-75% solids by weight is preferred. The reactions can be carried out without a solvent, however, gelatinous end products may result which is generally undesirable.
The reactions can be carried out at various temperatures; however, temperatures from about 50.degree. to 90.degree. C. are most satisfactory. The following general reaction illustrating the quaternization of the amido-amine intermediate with benzyl chloride, a preferred agent, is typical: